1. Field of the Invention
The present invention relates to the field of digital imaging. More specifically, the present invention relates to the generation and provision of still images.
2. Background Information
In recent years, continuing advances in computing and communication technology have dramatically improved the affordability of high performance computing/communication devices. Increasingly, these relatively low cost high performance computing/communication devices are being used to conduct video communication, e.g. video telephony. Typically, the video communication are conducted over a low bit rate connection, e.g. a standard telephone connection. Due to the bandwidth constraints of the low bit rate connection, the video images exchanged between the communication endpoints are not of the highest quality. Reference is made to International Telecommunication Union - Telecommunication Standardization Section (ITU-T) Recommendation H.324, entitled "Terminal for low bit rate multimedia communication" (currently in draft form).
Nevertheless, quite often, a participant to a video communication will find it desirable to take a snap shot of the remote video images, i.e. to obtain a still image. Under the prior art, because the remote video images received are not of the highest quality, the snap shot or the still image obtained will not be of the highest quality either.sup.1. Such snap shots are especially inferior, when compared with still images generated and sent in accordance with any one of a number of still image techniques or standards known in the art. Typically, these higher quality still images are generated using specialized image generation software, and exchanged over a data link between the communication devices. Reference is made to the ITU-T Recommendation T.81, entitled "Information technology--Digital compression and coding of continuous-tone still images--Requirements and guidelines", and Recommendation T.84, entitled "Information technology--Digital compression and coding of continuous-tone still images--Extensions". FNT .sup.1 Note that it is the recipient of the remote video images who is taking the snap shots or generating the still images.
Thus, under the prior art, if high quality snap shots or still images are desired, the video communication must be conducted over a much higher bit rate connection to facilitate the provision of better video images, which means high speed connections such as T1 or Integrated Service Digital Network (ISDN) lines, as standard telephone connections are unable to meet the high bandwidth requirement, or in the alternative, separate image generation software and data link, in addition to the video communication software and video link, must be employed.
Therefore, it is desirable to have a more efficient and effective way for generating high quality "snap shots" of video images.